The subject should be something like:
"selftests/landlock: Test listening on socket without binding"
On Mon, Apr 08, 2024 at 05:47:47PM +0800, Ivanov Mikhail wrote:
> Suggested code test scenarios where listen(2) call without explicit
> bind(2) is allowed and forbidden.
>
> Signed-off-by: Ivanov Mikhail <ivanov.mikhail1@xxxxxxxxxxxxxxxxxxx>
> Reviewed-by: Konstantin Meskhidze <konstantin.meskhidze@xxxxxxxxxx>
> ---
> tools/testing/selftests/landlock/net_test.c | 89 +++++++++++++++++++++
> 1 file changed, 89 insertions(+)
>
> diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c
> index 936cfc879f1d..6d6b5aef387f 100644
> --- a/tools/testing/selftests/landlock/net_test.c
> +++ b/tools/testing/selftests/landlock/net_test.c
> @@ -1714,6 +1714,95 @@ TEST_F(port_specific, bind_connect_zero)
> EXPECT_EQ(0, close(bind_fd));
> }
>
> +TEST_F(port_specific, listen_zero)
> +{
> + int listen_fd, connect_fd;
> + uint16_t port;
> +
> + /* Adds a rule layer with bind actions. */
> + if (variant->sandbox == TCP_SANDBOX) {
> + const struct landlock_ruleset_attr ruleset_attr = {
> + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP,
> + };
> + const struct landlock_net_port_attr tcp_bind_zero = {
> + .allowed_access = LANDLOCK_ACCESS_NET_BIND_TCP,
> + .port = 0,
> + };
> + int ruleset_fd;
> +
> + ruleset_fd = landlock_create_ruleset(&ruleset_attr,
> + sizeof(ruleset_attr), 0);
> + ASSERT_LE(0, ruleset_fd);
> +
> + /* Checks zero port value on bind action. */
> + EXPECT_EQ(0,
> + landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT,
> + &tcp_bind_zero, 0));
> +
> + enforce_ruleset(_metadata, ruleset_fd);
> + EXPECT_EQ(0, close(ruleset_fd));
> + }
> +
> + listen_fd = socket_variant(&self->srv0);
> + ASSERT_LE(0, listen_fd);
> +
> + connect_fd = socket_variant(&self->srv0);
> + ASSERT_LE(0, listen_fd);
> + /*
> + * Allow listen(2) to select a random port for the socket,
> + * since bind(2) wasn't called.
> + */
> + EXPECT_EQ(0, listen(listen_fd, backlog));
> +
> + /* Sets binded (by listen(2)) port for both protocol families. */
> + port = get_binded_port(listen_fd, &variant->prot);
> + EXPECT_NE(0, port);
> + set_port(&self->srv0, port);
> +
> + /* Connects on the binded port. */
> + EXPECT_EQ(0, connect_variant(connect_fd, &self->srv0));
> +
> + EXPECT_EQ(0, close(listen_fd));
> + EXPECT_EQ(0, close(connect_fd));
> +}
> +
> +TEST_F(port_specific, deny_listen_zero)
> +{
> + int listen_fd, ret;
> +
> + /* Adds a rule layer with bind actions. */
> + if (variant->sandbox == TCP_SANDBOX) {
> + const struct landlock_ruleset_attr ruleset_attr = {
> + .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP,
> + };
> + int ruleset_fd;
> +
> + ruleset_fd = landlock_create_ruleset(&ruleset_attr,
> + sizeof(ruleset_attr), 0);
> + ASSERT_LE(0, ruleset_fd);
> +
> + /* Forbid binding to any port. */
> + enforce_ruleset(_metadata, ruleset_fd);
> + EXPECT_EQ(0, close(ruleset_fd));
> + }
> +
> + listen_fd = socket_variant(&self->srv0);
> + ASSERT_LE(0, listen_fd);
> + /*
nit: Extra space
> + * Check that listen(2) call is prohibited without first calling bind(2).
This should fit in 80 columns.
> + */
> + ret = listen(listen_fd, backlog);
> + if (is_restricted(&variant->prot, variant->sandbox)) {
> + /* Denied by Landlock. */
> + EXPECT_NE(0, ret);
> + EXPECT_EQ(EACCES, errno);
> + } else {
> + EXPECT_EQ(0, ret);
> + }
> +
> + EXPECT_EQ(0, close(listen_fd));
> +}
These tests look good!
> +
> TEST_F(port_specific, bind_connect_1023)
> {
> int bind_fd, connect_fd, ret;
> --
> 2.34.1
>
>
